Method and apparatus for system information delivery

ABSTRACT

A method for providing system information (SI) by a base station in a wireless communication network is disclosed. The SI includes minimum SI and at least one other SI block. The method includes broadcasting the minimum SI having an area identification (ID) and at least one value tag, and receiving a radio resource control (RRC) message requesting the at least one other SI block from a user equipment (UE) when the area ID is different from a stored area ID on the UE or when the value tag is different from a stored value tag on the UE.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This is a Division of U.S. application Ser. No. 15/723,428 filed on Oct.3, 2017, which claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 62/405,394 filed Oct. 7, 2016. The contents of allabove-named applications are fully incorporated herein by reference forall purposes.

FIELD

The present application generally relates to wireless communications,and pertains particularly to system information delivery.

BACKGROUND

In a wireless network, such as an evolved-universal terrestrial radioaccess network (E-UTRAN), a user equipment (UE) needs to perform asystem information (SI) acquisition procedure to acquire variousparameters of Access Stratum (AS) and Non Access Stratum (NAS). Theseparameters are common for all the UEs in the same cell and aretraditionally broadcast in all the wireless technologies. The UE mayacquire SI for various purposes, such as system access (e.g., afterhandover, after entering E-UTRA from another RAT) and idle modeprocedures (e.g., cell selection and re-election, and etc.).

Traditionally, system information can be grouped into a MasterInformation Block (MIB) and a number of System Information Blocks(SIBs). For example, in a long term evolution (LTE) network, systeminformation may include a MIB and multiple SIBs (e.g., SIB1 throughSIB20). The MIB defines the most essential physical layer information ofthe cell that is required to received other system information parts.The MIB provides the system frame number (SFN), downlink (DL) systembandwidth, and physical HARQ indicator channel (PHICH) configuration. Itmay be transmitted every 40 ms and the scheduling information isstandardized. The SIBs are characterized by the type of information eachSIB carries. For example, SIB1 contains information for evaluatingwhether a UE is allowed to access or camp on a cell and further definesthe scheduling of other SIBs. SIB1 also contains cell access-relatedinformation (e.g., PLMN identity list, public land mobile network (PLMN)identity, cell identity, cell status, and etc.), cell selectioninformation (minimum receiver level), and scheduling information (SImessage type and periodicity, SI window length, and etc.). SIB2 providesinformation about common and shared channels which includes randomaccess channel (RACH), physical RACH (PRACH), broadcast control channel(BCCH), physical downlink shared channel (PDSCH), physical uplink sharedchannel (PUSCH) and etc. SIBs 3 to 8 provide information required forcell reselection. SIB3 provides information on intra-frequency cellreselection except neighbor cell information. SIB4 provides informationon neighbor cell information. SIBS is for inter-frequency cellreselection. SIB6, SIB7, and SIB8 are respectively for UTRAN, GERAN, andCDMA related cell (re)selection.

A UE may read system information during an initial attach process. Oncethe UE is camped to a new cell, it reads the relevant SI. If some SIvalues have changed, the network may page the UEs to inform the UEsabout the changes. The UEs may read the SI during the next modificationcycle. The modification cycle is a cell specific parameter that issignaled in the SIB2. Once the UE receives a paging indicating a SIBmodification, it may invalidate all the SI and retrieve all the SIagain.

New Radio (NR) has been discussed in the 3rd Generation PartnershipProject (3GPP) as a key technology for supporting the operation of thenext generation wireless network. In NR systems and networks, fast andefficient SI distribution is desirable. However, specific SIdistribution mechanisms have not been extensively studied.

As mentioned above, conventionally, cells broadcast SI in all thewireless technologies, without taking into consideration of theconditions and/or characteristics of the UEs in their coverage areas.Such SI delivery method undesirably consumes radio resource andincreases operation overhead.

Thus, there is a need in the art for an effective SI delivery method toprovide SI to UEs, where the SI delivery method takes into considerationof the conditions and/or characteristics of the UEs.

SUMMARY

The present application is related to method and apparatus for systeminformation delivery.

In a first aspect of the present application, a method for providingsystem information (SI) by a base station in a wireless communicationnetwork is disclosed. The SI includes minimum SI and at least one otherSI block. The method includes broadcasting the minimum SI having an areaidentification (ID) and at least one value tag, and receiving a radioresource control (RRC) message requesting the at least one other SIblock from a user equipment (UE) when the area ID is different from astored area ID on the UE or when the value tag is different from astored value tag on the UE.

In a second aspect of the present application, a base station forwireless communication in a wireless communication network is disclosed.The base station includes one or more non-transitory computer-readablemedia having computer-executable instructions embodied thereon, at leastone processor coupled to the one or more non-transitorycomputer-readable media, and configured to, execute thecomputer-executable instructions to: broadcast minimum systeminformation (SI) having an area identification (ID) and at least onevalue tag, and receive a radio resource control (RRC) message requestingat least one other SI block from a user equipment (UE) when the area IDis different from a stored area ID on the UE or when the value tag isdifferent from a stored value tag on the UE.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the exemplary disclosure are best understood from thefollowing detailed description when read with the accompanying Figures.Various features are not drawn to scale, dimensions of various featuresmay be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 illustrates a schematic diagram of a wireless communicationsystem, in accordance with an exemplary implementation of the presentapplication.

FIG. 2A illustrates an OSA ID format, in accordance with an exemplaryimplementation of the present application.

FIG. 2B illustrates an OSA ID format, in accordance with anotherexemplary implementation of the present application.

FIG. 3 is a flowchart diagram illustrating a method performed by a UEfor other SI acquisition, in accordance with an exemplary implementationof the present application.

FIG. 4 is a diagram illustrating mechanisms for other SI acquisitionthrough UE-oriented signaling, in accordance with implementations of thepresent application.

FIG. 5 illustrates a block diagram of a node for wireless communication,in accordance with various aspects of the present application.

DESCRIPTION

The following description contains specific information pertaining toimplementations in the present application. The drawings in the presentapplication and their accompanying detailed description are directed tomerely exemplary implementations. Unless noted otherwise, like orcorresponding elements among the figures may be indicated by like orcorresponding reference numerals. Moreover, the drawings andillustrations in the present application are generally not to scale, andare not intended to correspond to actual relative dimensions.

For the purpose of consistency and ease of understanding, like featuresare identified (although, in some examples, not shown) by numerals inthe exemplary figures. However, the features in differentimplementations may be differed in other respects, and thus shall not benarrowly confined to what is shown in the figures.

The description uses the phrases “in one implementation,” or “in someimplementations,” which may each refer to one or more of the same ordifferent implementations. The term “coupled” is defined as connected,whether directly or indirectly through intervening components, and isnot necessarily limited to physical connections. The term “comprising,”when utilized, means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in theso-described combination, group, series and the equivalent.

Additionally, for the purposes of explanation and non-limitation,specific details, such as functional entities, techniques, protocols,standard, and the like are set forth for providing an understanding ofthe described technology. In other examples, detailed description ofwell-known methods, technologies, system, architectures, and the likeare omitted so as not to obscure the description with unnecessarydetails.

Persons skilled in the art will immediately recognize that any networkfunction(s) or algorithm(s) described in the present disclosure may beimplemented by hardware, software or a combination of software andhardware. Described functions may correspond to modules may be software,hardware, firmware, or any combination thereof. The softwareimplementation may comprise computer executable instructions stored oncomputer readable medium such as memory or other type of storagedevices. For example, one or more microprocessors or general purposecomputers with communication processing capability may be programmedwith corresponding executable instructions and carry out the describednetwork function(s) or algorithm(s). The microprocessors or generalpurpose computers may be formed of applications specific integratedcircuitry (ASIC), programmable logic arrays, and/or using one or moredigital signal processor (DSPs). Although some of the exemplaryimplementations described in this specification are oriented to softwareinstalled and executing on computer hardware, nevertheless, alternativeexemplary implementations implemented as firmware or as hardware orcombination of hardware and software are well within the scope of thepresent disclosure.

The computer readable medium includes but is not limited to randomaccess memory (RAM), read only memory (ROM), erasable programmableread-only memory (EPROM), electrically erasable programmable read-onlymemory (EEPROM), flash memory, compact disc read-only memory (CD ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication network architecture (e.g., a long term evolution(LTE) system, a LTE-Advanced (LTE-A) system, or a LTE-Advanced Prosystem) typically includes at least one base station, at least one userequipment (UE), and one or more optional network elements that provideconnection towards a network. The UE communicates with the network(e.g., a core network (CN), an evolved packet core (EPC) network, anEvolved Universal Terrestrial Radio Access network (E-UTRAN), aNext-Generation Core (NGC), or an internet), through a radio accessnetwork (RAN) established by the base station.

It should be noted that, in the present application, a UE may include,but is not limited to, a mobile station, a mobile terminal or device, auser communication radio terminal. For example, a UE may be a portableradio equipment, which includes, but is not limited to, a mobile phone,a tablet, a wearable device, a sensor, or a personal digital assistant(PDA) with wireless communication capability. The UE is configured toreceive and transmit signals over an air interface to one or more cellsin a radio access network.

A base station may include, but is not limited to, a node B (NB) as inthe LTE, an evolved node B (eNB) as in the LTE-A, a radio networkcontroller (RNC) as in the UMTS, a base station controller (BSC) as inthe GSM/GERAN, a new radio evolved node B (NR eNB) as in the NR, a nextgeneration node B (gNB) as in the NR, and any other apparatus capable ofcontrolling radio communication and managing radio resources within acell. The base station may connect to serve the one or more UEs througha radio interface to the network.

A base station may be configured to provide communication servicesaccording to at least one of the following radio access technologies(RATs): Worldwide Interoperability for Microwave Access (WiMAX), GlobalSystem for Mobile communications (GSM, often referred to as 2G), GSMEDGE radio access Network (GERAN), General Packet Radio Service (GRPS),Universal Mobile Telecommunication System (UMTS, often referred to as3G) based on basic wideband-code division multiple access (W-CDMA),high-speed packet access (HSPA), LTE, LTE-A, New Radio (NR, oftenreferred to as 5G), and/or LTE-A Pro. However, the scope of the presentapplication should not be limited to the above mentioned protocols.

The base station is operable to provide radio coverage to a specificgeographical area using a plurality of cells forming the radio accessnetwork. The base station supports the operations of the cells. Eachcell is operable to provide services to at least one UE within its radiocoverage. More specifically, each cell (often referred to as a servingcell) provides services to serve one or more UEs within its radiocoverage, (e.g., each cell schedules the downlink and optionally uplinkresources to at least one UE within its radio coverage for downlink andoptionally uplink packet transmissions). The base station cancommunicate with one or more UEs in the radio communication systemthrough the plurality of cells. A cell may allocate sidelink (SL)resources for supporting proximity service (ProSe). Each cell may haveoverlapped coverage areas with other cells.

As discussed above, the frame structure for NR is to support flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements, such as enhanced mobile broadband (eMBB),massive machine type communication (mMTC), ultra reliable communicationand low latency communication (URLLC), while fulfilling highreliability, high data rate and low latency requirements. The orthogonalfrequency-division multiplexing (OFDM) technology as agreed in 3GPP mayserve as a baseline for NR waveform. The scalable OFDM numerology, suchas the adaptive sub-carrier spacing, the channel bandwidth, and theCyclic Prefix (CP) may be also used. Additionally, two coding schemesare considered for NR: (1) low-density parity-check (LDPC) and (2) PolarCode. The coding scheme adaption may be configured based on the channelconditions and/or the service applications.

Moreover, it is also considered that in a transmission time interval Txof a single NR frame, a downlink (DL) transmission data, a guard period,and an uplink (UL) transmission data should at least be included, wherethe respective portions of the DL transmission data, the guard period,the UL transmission data should also be configurable, for example, basedon the network dynamics of NR. In addition, sidelink resource may alsobe provided in a NR frame to support ProSe services.

Referring to FIG. 1 , FIG. 1 illustrates a schematic diagram of awireless communication system, in accordance with an exemplaryimplementation of the present application. In FIG. 1 , wireless network100 includes UE 102 a, UE 102 b, UE 102 c, base station 104 a, basestation 104 b, base station 104 c, base station 104 d, and base station104 e. In the present exemplary implementation, base stations 104 a, 104b, 104 c, 104 d, and 104 e are located in cells 1, 2, 3, 4, and 5,respectively. In wireless network 100, cells 1, 2, and 3 are withinother SI area (OSA) 1, while cells 4 and 5 are within OSA 2.

In OSA 1, cell 1, cell 2, and cell 3 provide minimum SI-a, minimum SI-b,and minimum SI-c, respectively, where the contents of minimum SI-a,minimum SI-b, and minimum SI-c are different from one another. In OSA 1,cell 1, cell 2, and cell 3 share the same other SI content (e.g., otherSI-a). For example, cells 1, 2, and 3 may provide through base stations104 a, 104 b, and 104 c, respectively, other SI-a to UEs in theirrespective cells. In one implementation, other SI-a includes one or moreother SI blocks. In one implementation, cells 1, 2, and 3 may provideentirely or at least partially the same other SI blocks to UEs in theircoverage areas. In another implementation, cells 1, 2, and 3 may provideat least one common other SI block to UEs in their coverage areas.

It should be noted that, in one implementation, a cell may belong tomore than one OSA, since the OSAs may overlap with one another. As such,a cell may provide different other SI blocks based on different OSAs.For example, a UE may request for one or more other SI blocks for aspecific OSA based on an OSA determination by the UE. The base stationmay transmit the requested other SI blocks of the specific OSA to theUE, based on the UE's OSA determination. In one implementation, any ofcells 1, 2, and 3 may belong to more than one OSA (e.g., OSA1 and OSA 3(not explicitly shown)), and may provide, in addition to other SI-a,other SI-c having different other SI content than other SI-a in anotherOSA (e.g., OSA 3). That is, any of cells 1, 2, and 3 may providedifferent other SI contents with respect to the different OSAs theybelong to.

In OSA 2, cell 4 and cell 5 provide minimum SI-d and minimum SI-e,respectively, where the contents of minimum SI-d and minimum SI-e aredifferent from each other. In OSA 2, cell 4 and cell 5 share the sameother SI content (e.g., other SI-b). For example, cells 4 and 5 mayprovide through base stations 104 d and 104 e, respectively, other SI-bto UEs in their respective cells. In the present implementation, otherSI-b of cells 4 and 5 is different from other SI-a of cells 1 through 3,since cells 4 and 5 belong to OSA 2 , which is different from OSA 1.

In the present exemplary implementation, UE 102 a moves from thecoverage area of cell 1 to the coverage area of cell 2. Since cells 1through 5 each provide their own minimum SI, as UE 102 a moves from cell1 to cell 2, UE 102 a is required to acquire minimum SI-b of cell 2, forexample, in order to camp on cell 2. For example, base station 104 b maybroadcast minimum SI-b of cell 2 periodically to UEs within the coveragearea of cell 2. After receiving minimum SI-b of cell 2, UE 102 a maydetermine whether it is required to further acquire other SI from cell2. For example, after moving from cell 1 to cell 2, UE 102 a maydetermine whether it is still within OSA 1, in which all of the cells(e.g., cells 1, 2, and 3) share the same other SI content (e.g., otherSI-a having one or more other SI-a blocks). If UE 102 a determines thatit is still within OSA 1 as it moves from cell 1 to cell 2, then UE 102a is not required to acquire the other SI from cell 2 since the otherSI-a stored therein is still valid.

In the present implementation, because cell 1 and cell 2 both belong toOSA 1, they share the same other SI content (e.g., other SI-a). Thus, UE102 a is not required to acquire the other SI from cell 2. That is, UE102 a can apply other SI-a obtained from cell 1 after it moves from cell1 to cell 2. In one implementation, UE 102 a may compare an OSA ID ofcell 2 with an OSA ID of cell 1, where the OSA ID of cell 1 is stored inUE 102 a, to determine whether it is within the same OSA. In oneimplementation, the OSA ID of cell 2 may be appended in minimum SI-b,which is provided to UE 102 a by cell 2.

In another implementation, cell 1 and cell 2 may belong to both OSA 1and OSA 3 (not explicitly shown in FIG. 1 ). UE 102 a may have otherSI-c stored therein from cell 1, instead of other SI-a of OSA 1. Aftercamping on cell 2 as it moved from cell 1 to cell 2, UE 102 a maydetermine whether cell 2 is still within OSA 3. If UE 102 a determinesthat it is still within OSA 3 as it moves from cell 1 to cell 2, then UE102 a is not required to acquire the other SI from cell 2 since theother SI-c stored therein is still valid.

In another implementation, instead of having UE 102 a determine whetherit needs to acquire the content of other SI from cell 2, cell 2 maycompare an OSA ID from UE 102 a with its OSA ID and determine whether UE102 a needs to acquire the other SI (e.g., other SI-a) from cell 2. UE102 a may report its stored OSA ID to cell 2. Cell 2 may compare the OSAID from UE 102 a with the OSA ID of cell 2. Cell 2 may provide its otherSI content (e.g., other SI-a) to UE 102 a, when cell 2 determines thatthe OSA ID provided by UE 102 a is different from the OSA ID of cell 2.Otherwise, cell 2 does not need to provide its other SI content (e.g.,other SI-a) to UE 102 a because the other SI (e.g., other SI-a) storedin UE 102 a is still valid.

In the present exemplary implementation, UE 102 b moves from thecoverage area of cell 3 to the coverage area of cell 4. Since cells 1through 5 each provide their own minimum SI, as UE 102 b moves from cell3 to cell 4, UE 102 b is required to acquire minimum SI-d of cell 4, forexample, in order to camp on cell 4. For example, base station 104 d maybroadcast minimum SI-d of cell 4 periodically to UEs within the coveragearea of cell 4. After receiving minimum SI-d of cell 4, UE 102 b maydetermine whether it is required to further acquire other SI (e.g.,other SI-b) from cell 4. For example, after moving from cell 3 to cell4, UE 102 b may determine whether it is still within OSA 1, in which allof the cells (e.g., cells 1, 2, and 3) share the same other SI content(e.g., other SI-a). If UE 102 b determines that it is still within OSA 1as it moves from cell 3 to cell 4, then UE 102 b is not required toacquire the other SI from cell 4. Otherwise, UE 102 b needs to acquirethe other SI from cell 4 since the other SI stored therein is no longervalid.

In the present implementation, cell 3 belongs to OSA 1 while cell 4belongs to OSA 2. Other SI-a of cell 3 and other SI-b of cell 4 havedifferent contents since cell 3 and cell 4 belong to different OSAs.Thus, UE 102 b is required to acquire the other SI (e.g., other SI-b)from cell 4, since other SI-a of cell 3 is no longer valid as UE 102 amoves from cell 3 in OSA 1 to cell 4 in OSA2. UE 102 b may need todiscard stored other SI-a therein, and acquire new other SI content(e.g., other SI-b) of cell 4. In one implementation, UE 102 b maycompare an OSA ID of cell 4 with an OSA ID of cell 3, where the OSA IDof cell 3 is stored in UE 102 b, to determine whether it is still withinthe same OSA. In one implementation, the OSA ID of cell 4 may beappended in minimum SI-d, which is provided to UE 102 b by cell 4.

In the present implementation, since the OSA ID of cell 3 is differentfrom the OSA ID of cell 4, as cells 3 and 4 reside in different OSAs, UE102 b determines that it is no longer in a cell in which the other SIcorresponding to the stored OSA ID is valid. As such, UE 102 b may senda request to cell 4 to acquire other SI (e.g., other SI-b) from cell 4.For example, when UE 102 b identifies that the OSA ID from cell 4 isdifferent from its stored OSA ID, UE 102 b may send a specific preambleor a radio resource control (RRC) message to cell 4 to request for otherSI-b.

In another implementation, instead of having UE 102 b determine whetherit needs to acquire the content of other SI from cell 4, cell 4 maycompare an OSA ID from UE 102 b with its OSA ID and determine whether UE102 b needs to acquire other SI-b from cell 4. UE 102 b may provide itsstored OSA ID to cell 4. Cell 4 may identify whether the OSA ID from UE102 b is the same as the OSA ID of cell 4. Cell 4 may provide its otherSI content (e.g., other SI-b) to UE 102 b, when cell 4 determines thatthe OSA ID provided by UE 102 b is different from the OSA ID of cell 4.Otherwise, cell 4 does not need to provide its other SI content (e.g.,other SI-b) to UE 102 b because the other SI stored in UE 102 b is stillvalid.

In the present exemplary implementation, UE 102 c moves within thecoverage area of cell 5. While within cell 5, UE 102 c may receiveupdates of minimum SI-e and/or other SI-b. Since cell 5 provides itsminimum SI (e.g., minimum SI-e) to UEs in its coverage area, UE 102 cmay receive minimum SI-e and/or any updates of minimum SI-e periodicallyfrom cell 5, for example, through base station 104 e. After receivingminimum SI-e of cell 5, UE 102 c may monitor a Value Tag of other SI(Value Tag) in an OSA ID appended in minimum SI-e to determine whetherit needs to acquire an updated version of other SI-b from cell 5. If theValue Tag from cell 5 is different from a Value Tag that is stored in UE102 c, UE 102 c needs to acquire updated other SI from cell 5, despitethe fact that UE 102 c is still within the coverage area of cell 5 andOSA 2. In one implementation, UE 102 c may request for the entire otherSI-b from cell 5. In another implementation, UE 102 c may request foronly the updated other SI parameters (e.g., delta information) from cell5 to conserve network resources and reduce latency. In anotherimplementation, UE 102 c may request for the other SI-b from cell 5without indicating any of its own information, cell 5 may determine totransmit the entire other SI-b to UE 102 c.

In another implementation, instead of having UE 102 c determine whetherit needs to acquire updated content of other SI from cell 5, cell 5 maycompare a Value Tag from UE 102 c with its current Value Tag anddetermine whether UE 102 c needs to acquire the updated content of otherSI-b. UE 102 c may report its stored OSA ID having the stored Value Tagto cell 5. Cell 5 may compare the stored Value Tag from UE 102 c withthe current Value Tag of cell 5. Cell 5 may provide the updated other SIcontent to UE 102 c, when cell 5 determines that the stored Value Tagfrom UE 102 c is different from cell 5's current Value Tag.

In one implementation, other SI-b includes one or more other SI blocks.In one implementation, cells 4 and 5 may provide entirely or at leastpartially the same other SI blocks to UEs in their coverage areas. Inanother implementation, cells 4 and 5 may provide at least one commonother SI block to UEs in their coverage areas.

According to implementations of the present application, the minimumsystem information may include, but is not limited, at least one of thefollowing fields:

-   -   (1) Information for facilitating initial access (e.g., access        admission control information, random access configuration, beam        parameters, frame timing information);    -   (2) Information for facilitating the validity of other SI;    -   (3) Cell identity which include PLMN ID, tracking area ID, cell        ID.

According to implementations of the present application, the othersystem information, the information that is not included in the minimumsystem, may be transmitted. The other system information may include,but is not limited, at least one of the following fields:

-   -   (1) Information for cell reselection (further comprise        intra-frequency, inter-frequency, inter-RAT information);    -   (2) Information regarding with Multimedia Broadcast/Multicast        Service (MBMS) services;    -   (3) Information regarding with GPS time and Coordinated        Universal Time (UTC);    -   (4) Information regarding with traffic steering between NR and        Wi-Fi;    -   (5) Information regarding with Device to Device (D2D) services;    -   (6) Information regarding with V2X services.

It is noted that the details of the OSA ID will be explained below.Also, the mechanisms for UE 102 a/102 b/102 c to determine whether it isrequired to acquire other SI will be explained in detail below.

FIG. 2A illustrates an OSA ID format, in accordance with an exemplaryimplementation of the present application. In FIG. 2A, OSA ID 200A is abitmap having eight bits (e.g., bits 0, 1, 2, 3, 4, 5, 6, and 7). Thefirst three bits (e.g., bits 0, 1, and 2) of OSA ID 200A represent anarea code or Area ID (e.g., 0-8), where the Area ID informs one or moreUEs which OSA they are in. The Area ID helps the UEs to determinewhether they are required to obtain or acquire other SI. It is notedthat an Area ID may be reused to identify more than one OSA, providedthat the OSAs are far apart from one another such that reusing the sameArea ID would not cause confusion to an UE as the UE moves from one cellto another. For example, an Area ID may not be reused by a cell'simmediately adjacent neighboring cells and their immediately adjacentneighboring cells.

The remaining bits (e.g., bits 3, 4, 5, 6, and 7) of OSA ID 200Arepresent a Value Tag of other SI (Value Tag), where the Value Taginforms the UEs the specific version of the other SI provided by thecell. The Value Tag may be similar to systeminfo valuetag defined in3GPP TS36.331, which is incorporated hereinwith by reference in itsentirety. The Value Tag helps the UEs to determine whether they arerequired to update the other SI parameters or values, even though theUEs may be still within the same OSA having the same Area ID. In oneimplementation, OSA ID 200A having the Area ID and Value Tag may bereferred to as an information field. It is noted that a cell maytransmit multiple other SIs within its coverage area, where differentother SIs may correspond to different OSA IDs. For example, cell 1, inFIG. 1 , may provide other SI-a corresponding to OSA 1, and other SI-ccorresponding to OSA 3.

In one implementation, a cell may append OSA ID 200A (i.e., informationfield) in the minimum SI, which may be broadcast periodically by thecell to the UEs in its coverage area. When a UE (e.g., UE 102 a/102b/102 c in FIG. 1 ) receives the OSA ID, the Area ID and Value Tag willbecome known to the UE. Thereafter, the UE may take different actions inresponse to different situations, as being enumerated in Table 1.

TABLE 1 Operations after receiving OSA ID Situation Operation (1) SameArea ID and (1) No need for other SI Value Tag acquisition (2) Same AreaID, (2) Need to request for new different Value Tag version of other SI(3) Different Area ID, (3) Need other SI acquisition same Value Tag (4)Different Area ID, (4) Need other SI acquisition different Value Tag

As shown in Table 1, under situation 1, a UE receives an OSA ID havingthe same Area ID and same Value Tag as those stored in the UE. Since theArea ID is the same as an Area ID stored in the UE, the UE determinesthat it is still within the same OSA. Since the Value Tag is the same asa Value Tag stored in the UE, the UE determines that the stored versionof other SI is still valid. Thus, there is no need for other SIacquisition.

Under situation 2, a UE receives an OSA ID having the same Area ID but adifferent Value Tag from a Value Tag stored in the UE. Since the Area IDis the same as an Area ID stored in the UE, the UE determines that it isstill within the same OSA. However, Since the Value Tag is differentfrom a Value Tag stored in the UE, the UE determines that at least aportion of the stored version of other SI is no longer valid. Thus, theUE needs to request for the new/updated version of the other SI from thecell. In one implementation, when the UE identifies that the Value Tagin the OSA ID from the cell is different from its stored Value Tag,while the Area ID is the same, the UE sends its stored Value Tag to thecell. Upon receiving the Value Tag from the UE, the cell may onlyprovide the updated parameters and values (e.g., delta information) ofthe other SI to the UE, instead of sending the entire new/updatedversion of the other SI to the UE, to save network resources and reducelatency. In another implementation, the cell may provide the entirenew/updated version of the other SI to the UE.

Under situation 3, a UE receives an OSA ID having a different Area ID,but the same Value Tag as what's stored in the UE. Since the Area ID inthe OSA ID from the cell is different from an Area ID stored in the UE,the UE determines that it is no longer within the OSA having the storedArea ID. In this situation, regardless of whether the Value Tag is thesame as the UE's stored Value Tag, the stored other SI is no longervalid since the UE has moved to a new OSA. Thus, the UE needs to requestfor the entirely new other SI from the cell in the new OSA. In oneimplementation, the UE may send a request for other SI without appendingany value tag information, and then the cell may provide the entireother SI by default.

Under situation 4, a UE receives an OSA ID having a different Area IDand a different Value Tag from what's stored in the UE. Since the AreaID in the OSA ID from the cell is different from an Area ID stored inthe UE, the UE determines that it is no longer within the OSA having thestored Area ID. Similar to situation 3, regardless of whether the ValueTag is the same as the stored Value Tag, the stored other SI is nolonger valid since the UE has moved to a new OSA. Thus, the UE needs torequest for the entirely new other SI from the cell in the new OSA. Inone implementation, the UE may send a request for other SI withoutappending any value tag information, and then the cell may provide theentire other SI by default.

In one implementation, the UE may send a request, in the form of aspecific preamble, to the cell to acquire the other SI. In anotherimplementation, the UE may send a request, in the form of an RRCmessage, to acquire the other SI. It is noted that each other SI mayhave a specific preamble dedicated thereto, and multiple specificpreambles may be assigned to the UE. The UE may send one of the assignedspecific preambles when the UE needs to request the corresponding otherSI. For using an RRC message as the request message, the UE may furtherindicate which other SI is required and optionally append the storedvalue tag for the other SI.

It is noted that, in some implementations, minimum SI may have its ownvalue tag, which may be also appended in the minimum SI.

FIG. 2B illustrates an OSA ID format, in accordance with anotherexemplary implementation of the present application. In FIG. 2B, OSA ID200B is a bitmap having three bits (e.g., bits 0, 1, and 2). Bits 0, 1,and 2 represent an area code or Area ID (e.g., 0-8), where the Area IDinforms one or more UEs which OSA they are in. In one implementation,OSA ID 200B having the Area ID may be referred to as an informationfield. In one implementation, a cell may append OSA ID 200B (i.e.,information field) in minimum SI, which may be broadcast periodically bythe cell to the UEs in its coverage area. When a UE (e.g., UE 102 a/102b/102 c in FIG. 1 ) receives the OSA ID, the Area ID of the cell willbecome known to the UE. The Area ID informs one or more UEs which OSAthey are in, so that the UEs can determine whether they are required toobtain or acquire other SI from the cell. In contrast to OSA ID 200A inFIG. 2A, OSA ID 200B does not include a Value Tag of other SI in the OSAID. Instead, the Value Tag may be sent to the UE upon request or demandfrom the UE. For example, a cell may provide the other SI by appendingthe corresponding Value Tag to the UE after receiving the request fromthe UE.

In one implementation, a Value Tag of other SI may be provided by thecell, for example, through an RRC message. For example, a UE (e.g., anRRC active UE) moves from cell 1 to cell 2. Cell 2 may check the UE'sValue Tag to see if the UE needs to acquire cell 2's other SI.Regardless of whether cell 1 and cell 2 are in the same OSA, cell 2(e.g., a serving cell) may negotiate with cell 1 (e.g., the source cell)about the Value Tag information for the UE when the UE moves to cell 2'scoverage and establishes an RRC connection with cell 2. In anotherimplementation, a UE may indicate a stored Value Tag to the cell.

In one implementation, a UE (e.g., an RRC active, inactive or idle UE)moves from cell 1 to cell 2. When the UE identifies that the Area ID ofcell 2 is different from its stored Area ID, the UE may transmit aspecific preamble to request for other SI. After receiving the specificpreamble, the cell may provide other SI to the UE in a dedicatedresource. When the UE identifies that the Area ID is the same as itsstored Area ID, it may snoop the other SI's Value Tag upon one or morededicated resources. If the Value Tag becomes different from its storedValue Tag, then the UE may transmit a specific preamble to request forthe other SI.

FIG. 3 is a flowchart diagram illustrating a method performed by a UEfor other SI acquisition, in accordance with an exemplary implementationof the present application. In FIG. 3 , flowchart 300 includes actions380, 382, 384, 386, 388, 390, 392, and 394. Flowchart 300 may apply toany of UEs 102 a, 102 b, and 102 c described with reference to FIG. 1 .

In action 380, a UE receives minimum SI from a cell, where the minimumSI includes an OSA ID (e.g., OSA ID 200A/200B in FIG. 2A/2B). The OSA ID(i.e., the information field) includes at least an Area ID. In action382, the UE determines whether the Area ID is different from an Area IDstored in the UE (e.g., stored Area ID).

If the UE determines that the Area ID appended in the minimum SI fromthe cell is different from the stored Area ID, then flowchart 300proceeds to action 384, where the UE requests for other SI from thecell. Upon request from the UE, the cell transmits the other SI to theUE. That is, the UE receives the other SI from the cell in action 386.

On the other hand, if the UE determines that the Area ID appended in theminimum SI from the cell is the same as the stored Area ID in action382, then flowchart 300 proceeds to action 388, where the UE determineswhether a Value Tag of other SI (Value Tag), for example, in the OSA IDappended in the minimum SI, is different from a Value Tag stored on theUE (e.g., stored Value Tag).

If the UE determines that the Value Tag from the cell is different fromthe stored Value Tag, then flowchart 300 proceeds to action 390, wherethe UE requests for updated parameters of the other SI from the cell.Upon request from the UE, the cell transmits the updated parameters ofthe other SI to the UE. That is, the UE receives the updated parametersof the other SI from the cell in action 392.

On the other hand, if the UE determines that the Value Tag from the cellis the same as the stored Value Tag in action 388, then flowchart 300proceeds to action 394, where the UE determines that it needs notrequest for other SI from the cell, since the other SI stored in the UEis still valid.

Various mechanisms for other SI acquisition signaling are describedbelow. The mechanisms for other SI acquisition signaling may becategorized into UE-oriented signaling and cell-oriented signaling.

For other SI acquisition through UE-oriented signaling, a UE may sendon-demand signaling to a cell to request for other SI. Thereafter, thecell may send or transmit the other SI to the UE. FIG. 4 is a diagramillustrating mechanisms for other SI acquisition through UE-orientedsignaling, in accordance with implementations of the presentapplication.

In FIG. 4 , diagram 400 includes actions 462, 464, 466, 468, 470, 472,474, 476, and 478. In diagram 400, actions 462, 464, 466, and optionally468 describe an on-demand signaling mechanism in which a UE may transmita specific preamble to request for other SI from a cell, according to anexemplary implementation of the present application. In diagram 400,actions 470, 472, 474, 476, and 478 describe an on-demand signalingmechanism in which a UE may transmit an RRC message to request for otherSI from a cell, according to an exemplary implementation of the presentapplication.

To facilitate other SI acquisition through UE-oriented on-demandsignaling using specific preambles, a cell needs to identify a UE andits stored Value Tag of other SI. In one implementation, each UE isassigned with a specific preamble, for example, by the cell. In action462, UE 402 may send its specific preamble (e.g. Preamble #1) to cell Xin OSA1, when UE 402 needs to acquire other SI from cell X. When cell Xreceives the specific preamble from UE 402, cell X may recognize UE 402based on the specific preamble assigned to UE 402. In action 464, cell Xmay send a random access response (RAR) to UE 402. Within the RAR, cellX may provide UE 402 with a scheduling opportunity (e.g., informationregarding a downlink resource and etc.). It should be noted thatnon-contention based random access is applied in the present UE-orientedon-demand signaling mechanism. In action 466, cell X may send other SIto UE 402 using the scheduled opportunity. In another implementation, acommon preamble may be assigned to all UEs for requesting theircorresponding other SI. The cell may broadcast the other SI whenreceiving the common preamble.

It should be noted that a prohibit timer may be used to prevent UE 402from sending another on-demand signaling to cell X to request for thesame other SI within a predetermined time set by the prohibit timer. Inone implementation, cell X may configure the prohibit timer to set thepredetermined time for on-demand signaling. As shown in FIG. 4 , inaction 468, UE 402 attempts to send its specific preamble to cell Xagain to request for the other SI from cell X after sending the specificpreamble in action 462. Because the prohibit timer has not expired, UE402 is prohibited from sending the request to cell X as shown in action468. It is noted that different prohibit timers may be used fordifferent other SIs, and the start and expiration of each prohibit timermay be independent of each other.

It should be noted that, in one implementation, cell X may recognize thestored Value Tag of other SI of UE 402 based on the specific preamblefrom UE 402. When cell X receives the specific preamble from UE 402,cell X may reply its current other SI to UE 402 regardless the Value Tagof other SI stored on UE 402.

It should be noted that, in one implementation, when UE 402 moves out ofOSA 1 into a new OSA (e.g., OSA 2), the specific preamble assigned to UE402 may be re-assigned to anther UE in cell X, for example. Theassignment of the specific preamble is performed through the minimum SI.

To facilitate other SI acquisition through UE-oriented on-demandsignaling using RRC messages, a UE may need to perform random accessprocedures to establish or re-establish an RRC connection with a cell.Once the UE establishes an RRC connection with the cell, the UE may usea specific RRC message to request for other SI from the cell.

In one implementation, the UE may only receive updated other SIparameters and/or values from the cell. In such case, the UE needs tosend its stored Value Tag of other SI to the cell, the cell maydetermine what values and/or parameters have been updated by comparingthe other SI corresponding to the stored Value Tag from the UE with thecell's current (most updated) other SI. In such case, the UE may need toenter the network, before sending its stored Value Tag to the cell.

With reference to FIG. 4 , in action 470, UE 402 (re-)establishes an RRCconnection with cell Y in OSA2, for example, and sends an RRC message tocell Y when it is connected to cell Y. In action 472, cell Y sends apreamble configuration to UE 402. Thereafter, UE 402 sends a preamble(e.g., preamble #2) to cell Y in action 474. In action 476, cell Y sendsan RAR to UE 402, where the RAR contains a scheduling opportunity (e.g.,information on a DL resource and etc.) for other SI. In action 478, cellY sends the other SI to UE 402 using the scheduled opportunity. Inanother implementation, a cell may broadcast the other SI afterreceiving the specific RRC message from the UE.

It should be noted that a prohibit timer (not explicitly shown in FIG. 4) may be used to prevent UE 402 from sending another on-demand signalingto cell Y to request for the other SI within a predetermined time set bythe prohibit timer. In one implementation, cell Y may configure theprohibit timer to set the predetermined time for on-demand signaling.The prohibit timer is triggered, when UE 402 sends the RRC message foron-demand signaling in action 470. The prohibit timer prohibits the UEfrom sending another on-demand signaling until the prohibit timerexpires. It is noted that different prohibit timers may be used fordifferent other SIs, and the start and expiration of each prohibit timermay be independent of each other.

It should be noted that, in one implementation, cell Y may recognize thestored Value Tag of other SI of UE 402 based on the RRC message from UE402. When cell Y receives the RRC message from UE 402, cell Y may replyits current other SI to UE 402 regardless the Value Tag of other SIstored in UE 402.

For other SI acquisition through cell-oriented signaling, a cell mayprovide other SI without receiving on-demand signaling from a UE. Forother SI acquisition through cell-oriented signaling, in oneimplementation, a cell may transmit the new other SI to all of itsconnected UEs when the version of other SI changes. The cell may eithertransmit the entire new other SI to all of its connected UEs, ortransmit only delta information (e.g., updated other SI parametersand/or values) to the connected UEs. The cell may use a specific groupradio network temporary identifier (RNTI), and schedule an other SItransmission for a group of UEs. The group RNTI may be configurable asthe cell may provide identification when the UEs perform RRC connectionestablishment.

For other SI acquisition through cell-oriented signaling, in anotherimplementation, a cell may apply cell-oriented signaling, when a UEestablishes or re-establishes an RRC connection with the cell. The cellmay initiate signaling other SI by using an RRC configuration message.

For other SI acquisition through cell-oriented signaling, in anotherimplementation, a cell may apply cell-oriented signaling, when the cellreceives information regarding changes in UE capability. Examples ofchanges in UE capability may include change in preferred networkslicing, change in preferred radio access technology (RAT), and etc. Insome implementations, different network slicings may apply differentcontents of other SI. For example, cells in the same OSA may have commonother SI for each respective network slicing.

FIG. 5 illustrates a block diagram of node 500 for wirelesscommunication, in accordance with various aspects of the presentapplication. The node 500 may have various configurations and may beincluded or be part of a base station and/or a UE. In someimplementations, node 500 may be an example of one or more aspects ofbase stations 104 a, 104 b, 104 c, 104 d, and/or 104 e described withreference to FIG. 1 . In some implementations, node 500 may be anexample of one or more aspects of UEs 102 a, 102 b, and/or 102 c in FIG.1 , and UE 402 in FIG. 4 . Node 500 may be configured to implement orfacilitate at least some of the features and functions described withreference to FIGS. 1, 2A, 2B, 3, and 4 .

As shown in FIG. 5 , node 500 may include transceiver 520, processor526, memory 528, one or more presentation components 534, and at leastone antenna 536. Node 500 may also include an RF spectrum band module, abase station communications module, a network communications module, anda system communications management module, input/output (I/O) ports, I/Ocomponents, and power supply (not explicitly shown in FIG. 5 ). Each ofthese components may be in communication with each other, directly orindirectly, over one or more buses 540.

Transceiver 520 having transmitter 522 and receiver 524 may beconfigured to transmit and/or receive time and/or frequency resourcepartitioning information. In some implementations, transceiver 520 maybe configured to transmit in different types of subframes and slotsincluding, but not limited to, usable, non-usable and flexibly usablesubframes and slot formats. Transceiver 520 may be configured to receivedata and control channels.

Node 500 may include a variety of computer-readable media.Computer-readable media can be any available media that can be accessedby node 500 and include both volatile and non-volatile media, removableand non-removable media. By way of example, and not limitation,computer-readable media may comprise computer storage media andcommunication media. Computer storage media includes both volatile andnon-volatile, removable and non-removable media implemented in anymethod or technology for storage of information such ascomputer-readable instructions, data structures, program modules orother data.

Computer storage media includes RAM, ROM, EEPROM, flash memory or othermemory technology, CD-ROM, digital versatile disks (DVD) or otheroptical disk storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices. Computer storage media doesnot comprise a propagated data signal. Communication media typicallyembodies computer-readable instructions, data structures, programmodules or other data in a modulated data signal such as a carrier waveor other transport mechanism and includes any information deliverymedia. The term “modulated data signal” means a signal that has one ormore of its characteristics set or changed in such a manner as to encodeinformation in the signal. By way of example, and not limitation,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer-readable media.

Memory 528 may include computer-storage media in the form of volatileand/or non-volatile memory. Memory 528 may be removable, non-removable,or a combination thereof. Exemplary memory includes solid-state memory,hard drives, optical-disc drives, and etc. As illustrated in FIG. 5 ,memory 528 may store computer-readable, computer-executable instructions532 (e.g., software codes) that are configured to, when executed, causeprocessor 526 to perform various functions described herein, forexample, with reference to FIGS. 1, 2A, 2B, 3, and 4 . Alternatively,instructions 532 may not be directly executable by processor 526 but beconfigured to cause node 500 (e.g., when compiled and executed) toperform various functions described herein.

Processor 526 may include an intelligent hardware device, e.g., acentral processing unit (CPU), a microcontroller, an ASIC, and etc.Processor 526 may include memory. Processor 526 may process data 530 andinstructions 532 received from memory 528, and information throughtransceiver 520, the base band communications module, and/or the networkcommunications module. Processor 526 may also process information to besent to transceiver 520 for transmission through antenna 536, to thenetwork communications module for transmission to a core network.

One or more presentation components 534 presents data indications to aperson or other device. Exemplary one or more presentation components534 include a display device, speaker, printing component, vibratingcomponent, and etc.

From the above description it is manifest that various techniques can beused for implementing the concepts described in the present applicationwithout departing from the scope of those concepts. Moreover, while theconcepts have been described with specific reference to certainimplementations, a person of ordinary skill in the art would recognizethat changes can be made in form and detail without departing from thescope of those concepts. As such, the described implementations are tobe considered in all respects as illustrative and not restrictive. Itshould also be understood that the present application is not limited tothe particular implementations described above, but many rearrangements,modifications, and substitutions are possible without departing from thescope of the present disclosure.

What is claimed is:
 1. A method for providing system information (SI) by one or more cells in a wireless communication network, the SI comprising minimum SI and at least a first other SI block, the method comprising: broadcasting, by a first cell, the minimum SI having an area identification (ID) and at least one value tag, the area ID being associated with the first cell and a second cell; receiving, at the first cell, a radio resource control (RRC) message requesting the first other SI block from a user equipment (UE) when the value tag is different from a stored value tag on the UE; and transmitting, after receiving the RRC message, the first other SI block to the UE, wherein before the receiving of the RRC message from the UE, the second cell provided the UE with a second other SI block, content of the second other SI block being at least partially the same as content of the first other SI block.
 2. The method of claim 1, wherein before receiving the RRC message, the UE moves from a coverage area of the second cell to a coverage area of the first cell.
 3. The method of claim 1, further comprising receiving, from the UE, a request for acquiring at least one updated parameter of the first other SI block when the value tag in the minimum SI is different from the stored value tag on the UE.
 4. The method of claim 3, further comprising transmitting the updated parameter of the first other SI block to the UE when the area ID is the same as the stored area ID and the value tag is different from the stored value tag on the UE.
 5. The method of claim 1, wherein the minimum SI includes an information field, and the information field includes at least one of the area ID and the value tag.
 6. The method of claim 5, wherein the information field only includes the area ID, and the value tag is provided in the first other SI block.
 7. The method of claim 1, wherein: the first and second cells are associated with at least one base station which broadcasts the minimum SI through the first cell; and the first and second cells have different coverage areas that at least partially overlap each other.
 8. The method of claim 1, wherein the second cell broadcasts second minimum SI that is different from the minimum SI broadcast by the first cell.
 9. The method of claim 1, wherein the value tag includes a version of the first other SI block.
 10. The method of claim 1, further comprising receiving, at the first cell, a specific preamble from the UE for acquiring the first other SI block when the area ID is different from a stored area ID or the value tag is different from the stored value tag.
 11. The method of claim 10, further comprising transmitting the first other SI block to the UE in a dedicated resource when the first cell receives the specific preamble.
 12. The method of claim 1, wherein the first and second cells are associated with the same other SI area (OSA).
 13. A base station for wireless communication in a wireless communication network, the base station comprising: one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and at least one processor coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to: broadcast, through a first cell associated with the base station, minimum system information (SI) having an area identification (ID) and at least one value tag, the area ID being associated with the first cell and a second cell; receive, via the first cell, a radio resource control (RRC) message from a user equipment (UE) requesting at least a first other SI block associated with the minimum SI when the value tag is different from a stored value tag on the UE; and transmit, after receiving the RRC message, the first other SI block to the UE, wherein before the receiving of the RRC message from the UE, the second cell provided the UE with a second other SI block, content of the second other SI block being at least partially the same as content of the first other SI block.
 14. The base station of claim 13, wherein before receiving the RRC message, the UE moves from a coverage area of the second cell to a coverage area of the first cell.
 15. The base station of claim 13, wherein the at least one processor is further configured to execute the computer-executable instructions to: receive, from the UE, a request for acquiring at least one updated parameter of the first other SI block when the value tag in the minimum SI is different from the stored value tag on the UE.
 16. The base station of claim 15, wherein the at least one processor is further configured to execute the computer-executable instructions to: transmit the updated parameter of the first other SI block to the UE when the area ID is the same as the stored area ID and the value tag is different from the stored value tag on the UE.
 17. The base station of claim 13, wherein the second cell broadcasts second minimum SI that is different from the minimum SI broadcast by the first cell.
 18. The base station of claim 13, wherein the at least one processor is further configured to execute the computer-executable instructions to: receive, through the first cell, a specific preamble from the UE for acquiring the first other SI block when the area ID is different from a stored area ID or the value tag is different from the stored value tag.
 19. The base station of claim 18, wherein the at least one processor is further configured to execute the computer-executable instructions to: transmit the first other SI block to the UE in a dedicated resource when the base station receives the specific preamble.
 20. The base station of claim 13, wherein the first and second cells are associated with the same other SI area (OSA). 